1. Field of the Invention
The present invention relates to a recording apparatus for recording information on a magnetooptical recording medium. More particularly, the present invention relates to a magnetooptical recording apparatus for recording music data on a magnetooptical recording medium.
2. Background of the Invention
A first type of known magnetooptical recording apparatus for recording information on a magnetooptical recording medium having a data region and a lead-in region, in general, records digital data in the data region. When recording digital music data or the like in the data region of the magnetooptical recording medium, a system controller produces what is called TOC (table of contents) data concerning the digital data, including tune number (track number) and time data representing recording start time and recording time, on the basis of the digital data to be recorded on the magnetooptical recording medium. The TOC information produced by the system controller is stored in a storage device such as a DRAM or the like. Upon completion of digital data recording in the data region of the magnetooptical recording medium, the recording head is shifted from the data region to the lead-in region, and then the TOC information stored in the storage device is recorded in the lead-in region of the magnetooptical recording medium. Such a magnetooptical recording apparatus is disclosed in, for example, Japanese Patent Laid-Open (Kokai) No. 4-119551.
A second type of known magnetooptical recording apparatus, when recording digital data on a magnetooptical recording medium having a data region carrying digital data, interrupts the recording operation at a specified time upon detection of a change in the TOC information representing the contents of the recorded digital data. Then, the magnetooptical recording apparatus, similarly to the first known magnetooptical recording apparatus, records the TOC information previously stored in the lead-in region of the storage device, and resumes the recording operation.
A third type of known magnetooptical recording apparatus, similarly to the second type of known magnetooptical recording apparatus, interrupts the recording operation for recording digital data in the recording region when the amount of TOC information, representing the contents of the digital data recorded in the data region of the magnetooptical recording medium, reaches a specified information content, and then shifts the recording head to the lead-in region to record the TOC information previously stored in the storage device in the lead-in region of the magnetooptical recording medium. Upon completion of the recording of TOC information in the lead-in region, the recording head is shifted to the data region to resume recording of the digital data in the recording region.
When the first type of known magnetooptical recording apparatus employing a DRAM is disconnected from the power supply, a backup device, such as a capacitor, is capable of supplying power for only a very short time. If a static RAM is employed instead of the DRAM, the magnetooptical recording apparatus needs a large scale circuit, which increases the cost of the magnetooptical recording apparatus.
The second type of known magnetooptical recording apparatus needs to record the TOC information every time the TOC information changes. Accordingly, the recording head moving mechanism for shifting the recording head, such as an optical pickup, needs to operate frequently when recording a large number of musical pieces. Consequently, the load on the recording head moving mechanism is increased and the recording operation needs to be interrupted frequently during operation of the recording head moving mechanism.
The third type of known magnetooptical recording apparatus records TOC information in the lead-in region every time the amount of TOC information reaches a specified information content. Since the amount of TOC information reaches the specified information content in a short time when recording a large number of musical pieces, the same problem as resides in the second type of known magnetooptical recording apparatus arises.
When recording a small number of musical pieces having a relatively large amount of data to be recorded, the time in which the amount of TOC information reaches the specified information content is relatively long. Therefore, if power supply to the magnetooptical recording apparatus is accidentally interrupted due to power failure, etc., all the TOC information stored in the storage device, such as a RAM, will be lost.